INTERACTIVE CAPTCHA SYSTEM RESILIENT TO PHISHING ATTACKS

摘要

The present invention relates to a method for providing completely automated public Turing test to tell computers and humans apart (CAPTCHA) technology to prevent phishing. A method for providing a CAPTCHA image comprises: a CAPTCHA image generating step for enabling an authentication server to generate a first partial CAPTCHA image and a second partial CAPTCHA image which separate a CAPTCHA image including a character string image corresponding to site key information; a CAPTCHA image transmitting step for enabling the authentication server to transmit the first partial CAPTCHA image to an authentication terminal, and transmit the second partial CAPTCHA image to a portable terminal having a camera; a CAPTCHA image displaying step for enabling the authentication terminal to display the first partial CAPTCHA image on a first screen which is positioned or connected to the authentication terminal, and enabling the portable terminal to display the second partial CAPTCHA image on a second screen which is positioned or connected to the portable terminal; and a partial CAPTCHA image overlapping step for enabling the portable terminal to photograph an image including a part of the first partial CAPTCHA image displayed on the first screen by using the camera, overlap the photographed image with the second partial CAPTCHA image, and display the same on the second screen. The present invention can authenticate users stably.